Plug-in air purifier



FIG. 1 is a perspective view, showing my new design;

FIG. 2 is a top view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a rear view thereof;

FIG. 6 is a left end view thereof; and,

FIG. 7 is a right end view thereof. 

CLAIM I claim, the ornamental design for a plug-in air purifier, as shown and described. 